import sys
readline = sys.stdin.readline

N,M = map(int,readline().split())
S = readline().rstrip()
DIV = 10 ** 9 + 7

G = [[] for i in range(N)]
for _ in range(M):
    u,v = map(int,readline().split())
    G[u - 1].append(v - 1)
    G[v - 1].append(u - 1)
dp = [0] * N
for i in range(N):
    if S[i] == "P":
        dp[i] = 1
        
T = "DCA"
for t in T:
    new_dp = [0] * N
    for v in range(N):
        if dp[v] == 0:
            continue
        for child in G[v]:
            if S[child] == t:
                new_dp[child] += dp[v]
                new_dp[child] %= DIV
    dp = new_dp
        
print(sum(dp) % DIV)